Cytheris SA, a privately held clinical-stage biopharmaceutical company focused on treating lymphopenia driven diseases, announced that the European Commission has granted an orphan designation for Cytheris' CYT017, glycosylated recombinant human interleukin-7 (glycosylated r-h-IL7), for the treatment of Progressive Multifocal Leukoencephalopathy (PML).
 
Additionally, Cytheris obtained scientific advice for a phase IIb study protocol with CYT107 in HIV-related PML. Cytheris has reached an agreement with the EMA on the key study endpoints. Cytheris will start this phase IIb study, intended to be pivotal, in early 2013.
 
PML is a severe demyelinating disease of the central nervous system caused by the JC virus. It occurs in many conditions leading to severe lymphopenia such as HIV infection, some cancers and organ transplantation treated with immunosuppressive therapies. PML is a very rare disease, affecting around four out of a million individuals. There is currently no marketed drug for the treatment of this devastating condition.

"This orphan designation strongly supports the development of CYT107 as the treatment for PML. The disease has a mortality rate of around 40 to 50 per cent at one year whilst survivors often present severe neurological complications and disabilities," said Therese Croughs, chief medical officer at Cytheris. "We already gathered clinical data supporting the efficacy and safety of CYT107 in PML through several compassionate use treatments. We are committed to conduct our pivotal clinical study as rapidly as possible."

"PML is an extremely serious disease driven by severe lymphopenia for which CYT107 is ideally placed to bring clear benefits through its targeted activity on immune T cell recovery and enhancement," said Damian Marron, CEO at Cytheris. "PML affects around 4,000 people in the US and EU alone. Bringing a treatment to this population would not only save and change patients' lives but would also respond to the pharmaceutical industry's desire to develop breakthrough drugs for targeted indications."
 
CYT107 is also in development in HIV Immune Non-Responders (HIV-INR) virologically controlled by anti-retroviral treatment. Fifteen to twenty five per cent of HIV patients are lymphopenic despite optimal treatment (HAART) leading to a significant increase in risk of death and serious complications. CYT107 also holds great promise in other lymphopenic conditions such as idiopathic lymphopenia or cancer associated lymphopenia.